CMC is more than a measure of corticospinal tract integrity in acute stroke patients.

In healthy subjects, motor cortex activity and electromyographic (EMG) signals from contracting contralateral muscle show coherence in the beta (15-30 Hz) range. Corticomuscular coherence (CMC) is considered a sign of functional coupling between muscle and brain. Based on prior studies, CMC is altered in stroke, but functional significance of this finding has remained unclear.

Post-Stroke Cognitive Impairment is Frequent After Infra-Tentorial Infarct.

Background And Purpose: Post-stroke cognitive impairment is a common and well-known consequence of supra-tentorial infarct, but its prevalence and severity after infra-tentorial infarct is unclear. We compared the frequencies and prognostic value of domain-specific cognitive deficits after supra-tentorial and infra-tentorial infarct.

Methods: In a consecutive cohort of patients with first-ever stroke (N = 244) admitted to Helsinki University Hospital, 37 patients had an infra-tentorial infarct.

Recovery of the 20 Hz Rebound to Tactile and Proprioceptive Stimulation after Stroke.

Sensorimotor integration is closely linked to changes in motor-cortical excitability, observable in the modulation of the 20 Hz rhythm. After somatosensory stimulation, the rhythm transiently increases as a rebound that reflects motor-cortex inhibition. Stroke-induced alterations in afferent input likely affect motor-cortex excitability and motor recovery.

Strength of ~20-Hz Rebound and Motor Recovery After Stroke.

Background: Stroke is a major cause of disability worldwide, and effective rehabilitation is crucial to regain skills for independent living. Recently, novel therapeutic approaches manipulating the excitatory-inhibitory balance of the motor cortex have been introduced to boost recovery after stroke. However, stroke-induced neurophysiological changes of the motor cortex may vary despite of similar clinical symptoms.

Modulation of the ∽20-Hz motor-cortex rhythm to passive movement and tactile stimulation.

Background: Integration of afferent somatosensory input with motor-cortex output is essential for accurate movements. Prior studies have shown that tactile input modulates motor-cortex excitability, which is reflected in the reactivity of the ∽ 20-Hz motor-cortex rhythm. ∽ 20-Hz rebound is connected to inhibition or deactivation of motor cortex whereas suppression has been associated with increased motor cortex activity.